The following invention relates to a method and apparatus for scanning and locating within a stored image field those areas of the image field which contain an object of interest.
A video camera coupled with a video storage device (sometimes referred to as a "frame grabber" ) can photograph an image and store that image in a memory for analysis by a computer. The stored image may be in the form of an array of bytes which represent the brightness levels of respective pixels in a pixel matrix. For example, video cameras having a charge coupled device (CCD) provide an output in the form of successive frames of video data in which each frame contains a series of analog signals representing the relative brightness of pixels in the CCD. These may be converted to digital data and stored in memory.
A desirable feature in such systems would be the ability to scan the image field in memory and quickly locate areas of interest. Normally, to locate an object of interest in an image field, the computer must scan the entire memory, even areas where there is a complete absence of lit pixels. This is because the computer normally has no way of determining where in the image field an object of interest might be. Scanning the entire memory is time consuming and inefficient for the computer, especially where the object of interest may be a video trace which is contained within a relatively narrow band of rows.